The invention relates to an arrangement for electrically locking the steering shaft of a motor vehicle steering device.
Known arrangements of this nature usually comprise an electric motor which is arranged in a housing and has an actuator connected downstream for displacing a blocking element from its locked position into its unlocked position and vice versa. In such arrangements, the blocking element, in its locked position, engages, for example, in the recess, formed by adjacent teeth, in a toothed ring attached to the steering shaft and thus blocks the steering shaft. In the known arrangements, an electronic switching arrangement is provided for (coded) activation of the corresponding electric motor or of the other electrical or electronic units (e.g. the position sensors), which switching arrangement is located inside the housing of the arrangement and, via electric lines, is connected to a power source which is at a distance from the arrangement and/or to a control arrangement of the vehicle.
A drawback of the known arrangements is that they are relatively expensive to produce, since individual vehicle manufacturers generally use different control electronics and different plug connections which are molded integrally on the housing, so that housings which are in each case specially adapted to the corresponding vehicles, and sometimes also special transmission arrangements, are required. Moreover, due to the integrated control electronics, the housings require a relatively large structural space. Finally, in these known arrangements, subsequent removal and refitting of the switching arrangement, which may be required for repair purposes, for example, is extremely time-consuming.
The invention is based on the object of providing an arrangement for electrically locking the steering shaft of a motor vehicle steering device, which arrangement is of compact design and can be used without major changes in vehicles produced by different manufacturers.
According to the invention, this object is achieved by means of the features of claim 1. Further, particularly advantageous configurations of the invention are disclosed by the subclaims.
The invention is fundamentally based on the principle of constructing the arrangement from two separate subassemblies: a locking device with a first housing, in which the electric motor with actuator connected downstream and blocking element is arranged, and an electronic switching device, which can be attached to the outside of the housing of the locking device.
If the arrangement according to the invention is made modular in this way, the locking device can easily be constructed as a standard module which can be used in a large number of different vehicles. By contrast, the switching device, which can be attached to the outside of the locking device, is manufacturer-specific.
In order to prevent the arrangement according to the invention from being interfered with, the switching device also has a suitable second housing, in which the actual electronics are arranged and which covers the electrical connection between switching device and locking device with respect to the outside.
It has proven particularly advantageous for the electrical connection between the locking device and the switching device to be formed by a plug connection, so that the switching device can easily be exchanged after it has been fitted. For this purpose, the switching device may, for example, be designed as a connector.
In an advantageous embodiment of the invention, the switching device and the locking device are connected to one another by means of locking elements, in such a manner that the two subassemblies cannot be separated from one another when the blocking element of the locking device is in its locked position.
To make the design of the locking device as compact as possible, it has proven advantageous for the actuator used to be a spindle drive with a threaded spindle which is connected by means of a toothed transmission and drives a driver mounted so that it can be displaced in linear fashion in a guide. This driver is connected to the blocking element in a manner known per se, by means of a spring.
Moreover, to guide the blocking element, the locking device comprises an adapter part which can be connected to the steering device of the vehicle and is designed in such a manner that, in the event of the steering shaft being twisted violently in the locked position of the blocking element, it absorbs the forces acting on this part.
In order for it to be possible, if appropriate, to adapt the arrangement according to the invention in a simple manner to vehicles produced by different manufacturers by mechanical means, it has proven advantageous for the adapter part and the blocking element to be arranged exchangeably on the locking device.